This invention relates to automatic digital switching/digital processing telecommunications systems and in particular to an interactive communication channel that provides line interface between the duplex serial data channels and the computer in such systems.
Systems of the type to which the invention applies generally comprise a common storage unit storing data and programs and processing units inter-operating with multiple duplex channel devices. U.S. Pat. No. 3,906,151 of Gunter Grossmann et al entitled Method and Apparatus of Signal Conversion in Program Controlled Automatic Data Exchanges, issued Sept. 16, 1975 discloses a system that is typical of the state of the art.
Such systems, however, have various limitations that the present invention seeks to overcome For example, current systems are sometimes: limited in the number of channels they can handle effectively; limited in the speed at which it can process data; transmit undetected errors; require additional processing hardware and memory to accommodate bit stuffing for code transparancy; and require special programs and processing techniques to accommodate different data transmission speeds on different data channels. Individually these limitations have been overcome to varying degrees in various existing systems For instance, the data transmission speed problem is solved by De Ver C. Finch et al in their U.S. Pat. No. 3,676,858 entitled Method, Apparatus and Computer Program for Determining the Transmission Rate and Coding Configuration of Remote Terminals, filed July 11, 1972. However, like current solutions to the various other limitations the solution requires the addition of complex techniques, programs and apparatus.
In view of the foregoing discussion, it is apparent that there currently exists the need for an improved I/O interface for automatic digital telecommunications systems that is not subject to the above itemized limitations. The present invention is directed toward satisfying that need.